1. Field of the Invention
This invention relates in general to wrenches and specifically to wrenches which are operable by rotation of a shaft inserted in the handle of the wrench.
2. Disclosure Statement
There have been many improvements to the conventional box or open end wrench in order to provide for quick tightening and loosening a nut or bolt in those instances where the wrench handle movement is limited to only a small arc. Such improvements include ratchet wrenches which are very well-known in the art. A conventional ratchet wrench includes a structure whereby oscillation of the handle of the wrench will cause rotation of the head of the wrench for driving an associated socket member or the like. Typically, the wrench head axis is transverse to the wrench handle. The handle oscillation mode of operation is very fast compared to a box or open end wrench, particularly in those instances where limited space is available for wrench handle movement and where other types of wrenches will not reach. It is equally well-known, however, that even ratchet wrenches are somewhat difficult to use in applications where oscillation of the handle is limited. More recently, speed ratchets have been developed to overcome the limitations of conventional ratchet wrenches. Such wrenches are provided with means associated with the handle whereby rotary movement may be imparted to the head of the wrench independent of oscillation of the handle, operation of the wrench being accomplished by rotation of the shaft of the wrench about the longitudinal axis of the handle instead of by the conventional oscillating of the handle. Many patents have been granted on such type of rotary handle ratchet wrenches, each patent providing a different solution to the various problems associated with the wrench structure. Several of these patented wrenches as listed as follows:
U.S. Pat. No. 2,808,749--Oct. 8, 1957--Lampke PA0 U.S. Pat. No. 3,272,037--Sept. 13, 1966--Bruehl PA0 U.S. Pat. No. 3,707,893--Jan. 2, 1973--Hofman PA0 U.S. Pat. No. 3,733,936--May 22, 1973--Flynn PA0 U.S. Pat. No. 4,086,829--May 2, 1978--Hudgins PA0 U.S. Pat. No. 4,137,801--Feb. 6, 1979--Imperio.
Typically, all of the above patents utilize protruding sockets for turning the nut or bolt, and include complex structures not required by the present invention.